Glass box extensions in Johnstone
From the first sketch to final sign-off, we plan and build glass extensions in Johnstone and the surrounding Renfrewshire and Inverclyde area.
- Guide price in JohnstoneFrom £29,000 inc VAT
- PlanningScottish householder rules; building warrant needed
- Build time10–16 weeks on site
- Postcode districtsPA5, PA10
Working in Johnstone
Site visits are available across Johnstone (PA5, PA10). Neighbouring towns we cover include Paisley (3 miles), Barrhead (5 miles), Erskine (6 miles), Renfrew (6 miles).
Clydebank, in Dunbartonshire, is roughly 7 miles from Johnstone and also on our list. Scotland's housing includes sandstone villas, terraces and tenements in the cities and plenty of post-war and modern houses and bungalows elsewhere. A building warrant is needed before work starts.
Guide prices for Johnstone
Prices below are for Johnstone, using the Scotland factor of ×0.98. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Johnstone: £2,940 to £5,680 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 4 m 8 m² | £29,000 – £35,500 | £29,000 – £37,000 | £33,500 – £45,500 |
| 3 m × 4 m 12 m² | £35,000 – £42,500 | £41,000 – £52,000 | £50,500 – £68,500 |
| 3 m × 6 m 18 m² | £52,500 – £64,000 | £61,500 – £78,000 | £75,500 – £102,500 |
For a figure based on your own dimensions, use our guide-price tool.
Will the council need to approve it?
In Scotland, householder permitted development rules (Class 1A for single-storey ground-floor extensions and Class 1B for extensions of more than one storey) allow some smaller extensions without a planning application, within limits on depth, height and distance from the boundary. Conservation areas and listed buildings are more restricted. Separately, almost every extension needs a building warrant from the council before work starts.
The planning position for a specific Johnstone address depends on its history and any designations, which is why we check it at the first visit.
Scotland has no Party Wall Act. Where work affects a shared wall or a neighbour's land, we agree access, protection and making good with your neighbour in writing before work starts.
Building close to a public sewer needs the agreement of Scottish Water, which we check during design.
Applications are decided by your council as planning authority.
When a glass extension makes sense
- Small infill spaces and side returns
- Period and listed-style houses where a light touch is wanted
- Garden-facing dining rooms
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Your questions about a glass extension in Johnstone
Who do I contract with for a glass extension in Johnstone?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Do you cover all of Johnstone?
Yes. We cover Johnstone and the surrounding parts of Renfrewshire and Inverclyde. Site visits are free and there is no obligation.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Johnstone, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How much does a glass extension cost?
Our guide range is about £2,940 to £5,680 per m² including VAT, because structural glass is made to order. A 12 m² standard-spec glass extension is typically £41,000 to £52,000 in Johnstone.
Are glass extensions cold in winter?
Modern double or triple glazing with warm-edge spacers and underfloor heating keeps them comfortable. They are not as warm as a solid room, and we explain the trade-off honestly.
Book a free site visit in Johnstone
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.